Binding post



Feb. 6, 1934. HARTER V 1,945,857

BINDING POST Filed Oct. 10, 1931 //v YEN 702 Patented Feb. 6, 1934 UNITED STATES 1;945,s57 I BINDING POST George F. Harter, Springfield, Mass, assignor to The Standard Electric Time Company, Spring- ,f' field, Mass.,a corporation of Connecticut Application October. 10, 1931. Serial No. 568,085

, 8 Claims. 01. 173-259) This invention relates to electrical terminals of the general type comprising a post having a clamping or contact element such as a cap or a head mounted for adjustment longitudinally thereof. These terminals are commonly provided with another contact or clamping element which may be adjustable relative to the post butwhich normally remains fixed in position relative thereto, the arrangement being such that the two 'con- 10 tact or clamping elements present relatively movable opposed surfaces between which an elec-" trical connection may be releasably secured. It

is also customary to secure the upper or outer element permanently to the post in some way which does not interfere with rotation or relative movement. This is a highly desirable feature as it gives assurance that these parts will 'not be lost or misplaced when using equipment of this character. It is likewise advantageous to cover the adjustable element with insulating material which may have a decorative or artistic appearance, as by molding or otherwise forming a head of suitable material which substantially encloses this element; and of course this'adds to the dilficulty of efiecting a permanent connection which affords the relative movement necessary to permit adjustment.

Objects of this invention are generally'to im-' prove the construction of devices of this character and to provide for manufacturing such devices in a more economical, efiicient and facile way. I

In the drawing Fig. 1 is a side elevational view of a binding post with a portion of the cap in vertical section, parts being omitted and broken away to illustrate the manner in which the device may be assembled; and

Fig. 2 is a view similar to Fig. 1 of the com- 40 pleted terminal.

The embodiment of the invention selected for illustration herein comprises a binding post 10 having a lower contact element in the form of a ring 11 mounted thereon in any approved manner, as by being integral therewith or by being threaded onto the post. The upper contact or clamping member is in the form of a cap having a substantially cylindrical body portion 12, and a lower radial flange 13. The cap is provided with a threaded bore 14 and a substantially smooth counterbore 16. The upper end of the cap is also counterbored to provide a shoulder 1'? which forms a seat for the closure member 18.

Near the upper end of the post the latter is .55; formed with an annular or circumferential groove 19'of' a depth to receive rotatable retaining elements in the form of balls 21. In the process of manufacturing this terminal the upper end of the post 10 is threaded as indicated at 22' to receive the cap 12, and, if 6 desired, the lower contact ring 11 may be screwed onto the post from the upper ,end so as to pass over the groove 19. The'parts' are arranged inthe position shown in Fig. 1 by threading the cap over the post to effect the necessary lon- 5 gitudinal adjustment to bring a side opening 20 in the cap into registry with or substantially opposite the groove l9. A number of balls 21 are then passed throughthe opening 20 and into the 'groove',-these ballspreferably being of a size substantially to fit between the counterbore 16 and-the base of the groovegso that these parts constitute-inner and outer raceways for the balls. While good results may be obtained by inserting in the groove only a single ball, or even a single non-rotatable element, it is preferred to insert a suflicient number of these balls or other elements having surfaces of revolution substantially to fill the groove. This having been done, the side opening 20 is closed by a plug 25in any approved manner, as by driving or threading the plug into the opening. and the closure member 18 is then pressed into the uppermost counterbore against the shoulder 17. This completely closes the counterbore 16 so that the latter forms a chamber about the post, the inner surface of this chamber being substantially coaxial with the outer surface 'of the post.- The cap is then enclosed or encased in a head 23 preferably of insulating material as, for example, a phenol condensation product or other moldable insulating material.

The cap is thus permanently secured onto the post, the closure member 18 and the lower end of the counterbore constituting abutment means for limiting travel of the balls along the counterbore as the cap is threaded along the post; Although it is preferred to use rotatable retaining elements, it will be understood that these elements may be provided in other forms, such as small rollers or cylindrical elements, in which case the groove of course would be shaped complementary to the elements employed. While the arrangement of the side opening 20 provides a very convenient and desirable means for introducing the retaining elements into a groove 19, it will be evident from this disclosure that other means may be provided for this purpose, as, for example, the post may be provided with a longitudinal groove leading to the circumferential groove 19, the elements being inserted through such longitudinal groove and the latter closed as by means of a plug. It will also be seen that the balls may be retained on the post by forming the upper end 24 of the post as a separate washer or unit which may be secured in place after the balls are inserted. Likewise many of the advantages of this invention may be gained by forming the groove 19 in the surface of the counterbore 16, and in this event it would be desirable to form a projecting flange or abutment on the upper end of the post for engagement with the balls to limit longitudinal travel thereof.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. A terminal of the class described comprising a threaded post, a contact member threaded thereon, means providing a raceway between these members, and rotatable elements in the raceway to provide for relative rotary movement of the post and contact member, and abutment means carried by one of these members forengagement with said rotary elements to limit relative longitudinal movement of the post and contact members. 7

2. A terminal of the class described comprising a post, a contact member mounted on the post for adjustment therealong, means providing an annular groove in one of these members to cooperate with the other member to provide-a raceway about the post, rotatable elements in the raceway, and means cooperating with the rotatable elements for limiting movement of the contact member along the post. 7

3. A terminal of the class described comprising a post, a contact member mounted for adjustment therealong, these members having spaced and opposed substantially coaxial surfaces, one of these surfaces having a cavity therein to receive a retaining element, a rotatable retaining element disposed in the cavity and engageable with the other of the opposed surfaces, and means for limiting travel of the retaining element longitudinally of the latter surface.

- 4. A terminal of the class described comprising a post, a contact member mounted for adjustment therealong, these members having spaced and opposed substantially coaxial surfaces, the

post surface having a cavity therein to receive a retaining element, a rotatable retaining element disposed in this cavity and engageable with the opposed surface of the contact member, and abutment means on the contact member for limiting travel of the rotatable element longitudinally thereof.

5. A terminal of the class described comprising a threaded post, a cap having a bore threaded to fit the post and. a counterbore providing an outer raceway for retaining elements, the post having an open circumferential groove forming an inner raceway for retaining elements, rotatable retaining elements between these raceways, and a closure for the counterbore.

6. A terminal of the class described comprising a threaded post, a cap having a bore threaded to fit the post and a counterbore providing an outer raceway for retaining elements, the post having an open circumferential groove forming an inner raceway for retaining elements, rotatable retaining elements between these raceways, a closure for the counterbore, and a head encasing the closure and the cap.

' '7. A terminal of the class described comprising a post, a cap for the post, means cooperating with these members for supporting the cap in different positions longitudinally of the post, these members having spaced and opposed substantially coaxialsurfaces, one of these surfaces having a cavity therein to receive a retaining element, one of the members having a passage therethrough to the cavity for inserting a retaining element, a rotatable retaining element disposed in the cavity and engageable with the other of the opposed surfaces, and means obstructing said passage for keeping said retaining element in the cavity.

8. A terminal of the class described comprising a post, a cap having a bore to receive the post, and a counterbore providing an outer raceway for retaining elements, means cooperating with these members for supporting the cap in different positions longitudinally of the post, the post having an open cavity therein to receive a retaining element, a rotatable retaining element disposed in the cavity and engageable with the outer surface provided by the counterbore, the cap having a passage therethrough to the cavity for inserting the retaining element, and means obstructingsaid passage for keeping the retaining element in the cavity.

GEORGE F. HAR'IER. 

